No flush valve that is installed to flush water closets or any other fixture or device shall be connected directly to any city water pipe or service pipe in the city unless the flush valve or device is provided with approved air breaks to overcome the vacuum created when the water is shut off; and no plumbing fixture, device or construction shall be installed which will provide a cross connection between the distributing system of water for drinking and domestic purposes and a drainage system, soil or waste pipe so as to permit or make possible the back flow of sewage or waste into the water supply system.
(1967 Code, § 16-21)  Penalty, see § 10.99